U.S. patent application number 11/951717 was filed with the patent office on 2008-10-09 for ballistic fabric.
Invention is credited to Mark Levine, David S. Peacock.
Application Number | 20080248708 11/951717 |
Document ID | / |
Family ID | 39386484 |
Filed Date | 2008-10-09 |
United States Patent
Application |
20080248708 |
Kind Code |
A1 |
Peacock; David S. ; et
al. |
October 9, 2008 |
Ballistic Fabric
Abstract
Briefly the invention relates to a flexible fabric for use as
for example in a roll-up shutter with improved ballistic
properties. More specifically, the present invention is directed to
a ballistic fabric that is formed from a unique cabled yarn and
allows less deformation on impact. The unique cabled yarn may be a
metal reinforced aramid yarn for giving the fabric additional
strength.
Inventors: |
Peacock; David S.;
(Hendersonville, TN) ; Levine; Mark;
(Hendersonville, TN) |
Correspondence
Address: |
FROMMER LAWRENCE & HAUG
745 FIFTH AVENUE- 10TH FL.
NEW YORK
NY
10151
US
|
Family ID: |
39386484 |
Appl. No.: |
11/951717 |
Filed: |
December 6, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60874108 |
Dec 11, 2006 |
|
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|
Current U.S.
Class: |
442/187 ;
139/420A; 442/189 |
Current CPC
Class: |
D10B 2331/021 20130101;
D02G 3/442 20130101; D02G 3/12 20130101; D03D 1/0052 20130101; Y10T
442/3049 20150401; D02G 3/047 20130101; D03D 15/593 20210101; E06B
9/13 20130101; Y10T 442/3065 20150401; D10B 2101/20 20130101 |
Class at
Publication: |
442/187 ;
442/189; 139/420.A |
International
Class: |
D03D 15/00 20060101
D03D015/00 |
Claims
1. A ballistic fabric for use in a roll-up shutter or the like, the
fabric comprising: a plurality of cabled yarns in MD and CD
directions; wherein said cabled yarns are formed by cabling high
tenacity aramid yarns with metal.
2. A method for producing a ballistic fabric, the method comprising
the steps of: cabling high tenacity aramid yarns with metal; and
weaving said cabled yarns in a preferred pattern to a predetermined
width.
3. A ballistic fabric for use in a roll-up shutter or the like, the
fabric comprising: a plurality of composite yarns in MD and CD
directions; wherein said composite yarns are formed from aramid
strands used as a core material within a thermoplastic sheath.
4. A method for producing a ballistic fabric, the method comprising
the steps of: producing composite yarns with aramid strands used as
a core material within a thermoplastic sheath; and weaving said
composite yarns in a preferred pattern to a predetermined
width.
5. The fabric according to claim 1, wherein said yarns are UV
coated for outdoor exposure of said fabric.
6. The fabric according to claim 1, wherein the metal is stainless
steel.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims priority benefits of U.S.
Provisional Patent Application Ser. No. 60/874,108 filed Dec. 11,
2006 entitled "Ballistic Fabric", the disclosure of which is
incorporated herein by reference.
BACKGROUND
[0002] 1. Field of the Invention
[0003] This invention relates generally to flexible fabrics with
improved ballistic properties. More specifically, the present
invention is directed to a ballistic fabric that is formed from a
unique cabled yarn and allows less deformation on impact.
[0004] 2. Background Discussion
[0005] In south-east states like Florida and Louisiana, there is a
need for protecting the openings of buildings such as windows and
doors and other means of access, especially after looking at the
aftermath of Hurricanes Charlie and Katrina. Often times such
openings are covered with breakable glass, and during a storm when
a loose object, such as a tree limb or the like, is blown into the
glass covering the opening, there is a danger that people within
the building will be injured or killed by the flying glass. For
example, the states along the Gulf of Mexico, during certain times
of the year, are prone to enormous and deadly storms known as
hurricanes. Hurricanes often have winds which blow above 75 mph and
between an average of 100 to 125 miles per hour, and in doing so,
are able to blow foreign objects such as street signs, tree limbs
and other types of debris into the windows of buildings, more
particularly to individual homes within cities and towns affected
by the storm.
[0006] Shutters are mainly used to prevent flying debris from
breaking the glass of the windows and letting the airflow into
manufacturing plants or residential houses. Most of the damage in
hurricanes is caused by the air blowing into the premises through
the broken windows and shutters, which then lifts off the roof and
can cause the plant or house to collapse. Preventing them from
breaking prevents the majority of the damage.
[0007] Rolling doors whose hanging portions are composed of
individual lamella-type sections of metal or plastics material
which are connected to each other by means of hinges transversely
of the rolling direction have been known for decades. Rolling doors
of this type can be moved only slowly because they have mechanical
hinges and produce unwanted, sometimes shrieking noises when they
are moved. These rolling doors are susceptible to damage during
everyday operation, particularly due to impacts from vehicles, such
as, stacker trucks. The repair of the damage is complicated because
deformed pans, such as, steel lamellas, are difficult to
replace.
[0008] Also known in the art are so-called high-speed doors which
are composed of a relatively thin flexible hanging material made
from webs of textile or plastics material. These doors can be moved
several times faster. In addition, they can be made air-tight
against wind. However, the major disadvantage of these high-speed
doors is the necessary complicated mechanism because the highly
flexible materials used in the doors are not capable of
transmitting thrust or pushing forces.
[0009] U.S. Pat. No. 6,286,579 discloses a retractable
storm/hurricane shade system mountable on an exterior wall above a
window, which contains vertical pockets into which PVC rods arc
inserted. The rods are of a length such that when they are engaged
with upper and lower ends of the window frame, they are slightly
bowed out and provide additional protection against the impact of
wind and flying objects. This set up, however, is not mechanically
stable to withstand the damage caused due to the impact of a
hurricane storm.
[0010] U.S. Pat. No. 6,296,039 discloses an apparatus for
wind-locking a curtain over an opening in a building. It is mounted
on an exterior wall above the window opening. A flexible corrugated
curtain contains horizontal tension rods running in tracks on each
side of the opening. The deployed curtain, similar to the previous
one, is secured at the top, bottom, and sides of the window. The
curtain in this case also does not have sufficient impact
resistance to withstand the colossal impact due to a storm.
[0011] U.S. Pat. No. 5,353,858 discloses a reinforced closing
element for an industrial two-dimensional wall opening. The closing
element is of a flexible material which can be rolled up and is
reinforced transversely of its rolling direction by
bending-resistant reinforcement layers which increase the
transverse stiffness and which are embedded on both sides of a core
zone within the closing element. This patent discloses that the
elements can be formed of either textile or metal fibers, in which
case, the closing element is either too flimsy or too stiff and
does not provide the essential ballistic properties required in a
door closing.
[0012] U.S. Pat. No. 6,374,551 discloses a moveable structural
reinforcement system with a moveable panel adapted to substantially
close a building opening. The panel has shear load resistance means
for regulating the shear stiffness of the building when the panel
is in the closed position to assist in resisting earthquake forces.
This property, however, is not useful in instances where the debris
impacts the building surface at high speeds.
[0013] U.S. Pat. No. 6,715,529 is a rolling shutter assembly
including a plurality of interconnected metal slats. The slats
travel in parallel tracks mounted on each side of the covered
opening. The shutter will withstand high wind velocities and forced
entries without disengagement of the slats from the track.
[0014] Although there are many references directed to protective
coverage for openings, no patents disclose or teach a roll-up
shutter that is both flexible and strong and allows entry of light,
making it ideal for example a hurricane shutter system. Therefore,
there was an immediate need for a shutter that is flexible and
strong, ideal for a hurricane shutter system, something that
incorporates reinforcing yarns and something that could be both
flexible and ballistic at the same time.
[0015] As an existent solution to this problem, aramid based
ballistic cloth/fabric have a well established application as a
protective barrier (bullet proof vests, military vehicle body
armor, aircraft engine containment, etc.) and therefore may be
used. Most of these materials are woven to less than 1 m widths in
very dense, multiply structures with no open area. However, as a
result of the stranded nature of aramid materials, producing wide
width (1-12 m) panels of open mesh designs for protection of large
objects like windows for housing, office, or business store fronts
is often not feasible. Yarns produced of aramid strands tend to
dimensionally flatten during weaving producing a fabric with little
open area/porosity and poor dimensional stability as a result of
the lack of crimp in the aramid yarns. Additionally, aramid yarns
are difficult to weave as the individual strands that make up an
aramid yarn, while having good tensile strength tend to abrade
resulting in continuous breaks across the width during weaving. The
wider the weaving width, the larger the variation in tension and
degree of breakage across the face of the fabric produced.
[0016] Therefore, there is a void space in this area and the
present invention provides for filling this void space with a
ballistic hurricane shutter that overcomes the drawbacks of the
prior art discussed above and therefore would be an advancement in
the state of the art.
SUMMARY OF THE INVENTION
[0017] Briefly the invention relates to a flexible fabric, for
example a roll-up shutter with improved ballistic properties. More
specifically, the present invention is directed to a ballistic
fabric that is formed containing unique cabled yarns. The unique
cabled yarn may be a metal reinforced aramid yarn giving the fabric
additional strength, and allowing less impact deformation.
[0018] Accordingly, one embodiment of the present invention is
directed to a cabled metal reinforced aramid yarn for use in
high-strength, high-modulus applications such as industrial,
commercial or consumer shutters.
[0019] Another embodiment is directed to a ballistic fabric made
from cabled metal reinforced aramid yarns that have enhanced
ballistic properties and may be used in industrial applications
such as industrial plant doors, shutters or coverings.
[0020] Yet another embodiment of the present invention is directed
to a hurricane shutter made from cabled metal reinforced aramid
yarns and has improved flexibility as well as enhanced ballistic
properties.
[0021] Yet another embodiment of the present invention provides for
the shutter having a variety of weave patterns based on the
required characteristics of the fabric.
[0022] Yet another embodiment of the present invention provides for
the shutter whose yarns are UV coated for outdoor exposure of such
a fabric.
[0023] Yet another embodiment of the present invention is directed
to a ballistic fabric made from yarns with aramid strands that are
used as a core material within a thermoplastic sheath. As with the
use of the cabled steel, the thermoplastic sheath allows for the
maximum strength of the aramid core to be realized, protects the
aramid from abrasion/cutting, maintains diameter uniformity, and
allows for crimp generation via plastic deformation of the
sheath.
[0024] Yet another embodiment of the present invention is directed
to a hurricane shutter made from yarns comprising aramid strands
that are used as a core material within a thermoplastic sheath,
which shutter has improved flexibility as well as enhanced
ballistic properties.
[0025] Other embodiments of the present invention include fabrics
described above but implemented using different weave patterns and
yarn combinations with one or more layers in conjunction with one
or more coatings to the cabled yarn.
BRIEF DESCRIPTION OF THE DRAWINGS
[0026] To the accomplishment of the foregoing and related ends,
certain illustrative aspects of the invention are described herein
in connection with the following description and the annexed
drawings. These aspects are indicative, however, of but a few of
the various ways in which the principles of the invention may be
employed and the present invention is intended to include all such
aspects and their equivalents. Other advantages and novel features
of the invention may become apparent from the following description
of the invention when considered in conjunction with the drawings.
The following description, given by way of example, but not
intended to limit the invention solely to the specific embodiments
described, may best be understood in conjunction with the
accompanying drawings, in which:
[0027] FIGS. 1-3 illustrate the problems associated with weaving an
aramid based ballistic fabric;
[0028] FIG. 4(a) illustrates the cabled metal reinforced aramid
yarn according to one embodiment of the present invention;
[0029] FIG. 4(b) illustrates the breaking of a cabled metal
reinforced aramid yarn at the aramid's maximum tensile
strength;
[0030] FIG. 5 illustrates the ballistic fabric according to one
embodiment of the present invention; and
[0031] FIG. 6 shows a cross-section of the yarn according to one
embodiment of the present invention.
DETAILED DESCRIPTION
[0032] It is noted that in this disclosure and particularly in the
claims and/or paragraphs, terms such as "comprises," "comprised,"
"comprising," and the like can have the meaning attributed to it in
U.S. patent law; that is, they can mean "includes," "included,"
"including," "including, but not limited to" and the like, and
allow for elements not explicitly recited. Terms such as
"consisting essentially of" and "consists essentially of" have the
meaning ascribed to them in U.S. patent law; that is, they allow
for elements not explicitly recited, but exclude elements that are
found in the prior art or that affect a basic or novel
characteristic of the invention. These and other embodiments are
disclosed or are apparent from and encompassed by, the following
description.
[0033] Aramid based ballistic cloth/fabric have a well established
application as a protective barrier (bullet proof vests, military
vehicle body armor, aircraft engine containment, etc.) and
therefore may be used in this area. Most of these materials are
woven to less than 1 m widths in very dense, multiply structures
with no open area. However, as a result of the yarns comprising
strands of aramid materials, producing wide width (1-12 m) panels
of open mesh designs for protection of large objects like windows
for housing, office, or business store fronts is often not
feasible. Yarns of aramid strands or filaments tend to
dimensionally flatten during weaving producing a fabric with little
open area/porosity and poor dimensional stability as a result of
the lack of crimp in the aramid yarns. Additionally, aramid yarns
are difficult to weave as the individual strands that make up an
aramid yarn, while having high tenacity tend to have continuous
breaks 10 across the width during weaving, as shown in FIGS. 1 and
2. The wider the weaving width, the larger the variation in tension
and degree of breakage across the face of the fabric produced. As
an example, the fabric showed in FIG. 3, formed from aramid yarns
in the machine direction ("MD") and metal or stainless steel yarns
in the cross-machine direction ("CD"), has fuzzy yarns 20 all over
the surface of the fabric due to frequent yarn breaks during
weaving. This creates undesired effects in the fabric and could
also cause the fabric to fail on impact. Therefore, the present
invention is directed to producing a fabric that is ballistically
functional while retaining the aesthetics, open area and porosity
of an open fabric.
[0034] The invention according to one embodiment of the invention
is a ballistic fabric 100 made from cabled metal reinforced aramid
yarns 80 that has enhanced ballistic properties and this fabric may
be used in industrial applications such as industrial plant doors,
or window shutters or coverings. In the cabled yarn 80, the metal
part or strand 60 imparts additional strength and yarn "crimping"
to stabilize the weave, while the aramid part 50 of the yarn
imparts flexibility as well as impact resistance to the fabric. In
any ballistic fabric, two features are most important in reducing
the fabric's deformation: reinforcement beams and the mass of the
fabric. The cabling of metal strands 60 with aramid strands 50
produce yarns which satisfy both these conditions in the present
invention.
[0035] The invention according to another embodiment of the
invention is a roll-up shutter fitted to cover the outside of
residential windows to protect the window glass from breakage by
tropical storm-type winds. The shutter can be made from cabled
metal reinforced aramid yarns 80 of the present invention, which
shutter has enhanced ballistic properties.
[0036] Specifically, the invention involves the use of modified
aramid yarns to address the shortcomings of the straight aramid
yarns outlined above. According to one embodiment, this invention
uses yarn 50 that uses aramid as a core material in a cabled
stainless steel structure 80. As shown in FIG. 4(a), steel strand
60 is wrapped, twisted or cabled around an aramid core 50 so as to
obtain the benefits such as: (a) maintaining the strength of the
aramid material 50 by allowing for more elongation of the steel
strands 60 under tensile stress, which allows for the steel 60 to
break at the aramid 50 break elongation (shown in FIG. 4(b)); (b)
protecting the aramid strands 50 from abrasion/cutting during
weaving; (c) maintaining diameter uniformity of the strands during
weaving to maintain mesh/count, open area, and air permeability;
(d) developing crimp in the final woven fabric via deformation of
the cabled steel; and (e) allowing for production of uniform fabric
in any width, especially widths wider than 1 m.
[0037] In a preferred embodiment of the present invention, the
ballistic fabric 100 is produced using for example a 0.76 mm yarn,
which is produced by cabling for example a 1420 denier Kevlar.RTM.
49 yarn 50 with for example a 6.times.0.20 mm 316L stainless steel
wire 60 with for example 5 twists/cm, as shown in FIG. 4(a). The
mesh count for a fabric thus produced may be for example 5.times.4
strands per cm.
[0038] Aramids used can be made of various grades/manufacturers
such as Nomex.RTM. although the Kevlar.RTM. 49 type is preferred
for maximum ballistic strength. Other materials for yarns such as
certain polyethylenes like Dyneema.RTM. and Spectra.RTM. may also
be used for this purpose. Steel type is not critical although
stainless is preferred. A UV coating may be applied to the fabric
or the component yarns individually for outdoor exposure of such a
fabric.
[0039] According to another embodiment, the invention uses yarns
comprising aramid strands that are used as a core material 30
within a thermoplastic sheath 40 as shown in FIG. 6. As with the
use of the cabled steel, the thermoplastic sheath 40 allows for
maximum strength of the aramid core 30 to be realized (via
elongation of the sheath, which is greater than the aramid),
protects the aramid 30 from abrasion/cutting, maintains diameter
uniformity, and allows for crimp generation via plastic deformation
of the sheath 40.
[0040] In a preferred embodiment of the invention, the ballistic
fabric 100 is produced as using for example a 0.76 mm strand 70
produced using for example a 1420 denier Kevlar.RTM. 49 yarn 30 of
0.33 mm diameter and for example a black UV stabilized polyethylene
terepthalate sheath 40 applied over the core Kevlar.RTM. strands
30. This yarn may be produced by for example a cross head extrusion
method or a coating process. The mesh count for a fabric thus
produced may be for example 5.times.4 strands per cm.
[0041] Aramids can be used of various grades/manufacturers such as
Nomex.RTM. although the Kevlar.RTM. 49 type is preferred for
maximum ballistic strength. Other materials for yarns such as
certain polyethylenes like Dyneema.RTM. and Spectra.RTM. may also
be used for this purpose. The UV coating may be applied to the
fabric or the component yarns individually for outdoor exposure of
such a fabric.
[0042] The fabric described in different embodiments of the
invention can be constructed with various weave patterns known in
the art including leno weaves. Combination of materials listed in
different embodiments, for example cabled aramid-steel yarns and
sheath core yarns, can also be employed to meet the desired
ballistic properties of the fabric structure. The fabric may also
be formed by combining cabled aramid-steel yarns 80 and sheath-core
yarns 70 in either CD or MD directions, as shown in FIG. 5 and
yarns in either direction may not be limited to the same type and
may comprise a combination of yarn types.
[0043] The fabric can also be made via techniques such as knitting
or braiding instead of weaving. Depending upon the width or length
of the shutter required techniques to form the braided or knitted
sections together may be employed.
[0044] Although illustrative embodiments of the invention have been
described in detail herein with reference to the accompanying
drawings, it is to be understood that the invention is not limited
to those precise embodiments, and that various changes and
modifications can be effected therein by one skilled in the art
without departing from the scope and spirit of the invention as
defined by the appended claims.
* * * * *